WORKING AROUND THE CLOCK: THE EFFECT OF SHIFT WORK AND SLEEP ON DEPRESSIVE SYMPTOMS

Abstract Shift work is increasingly prevalent in a 24-hour society where there is increased demand for round the clock service. However, shift work can disrupt circadian rhythms, which can negatively impact sleep. In turn, diminished sleep is associated with poor mental health. To expand prior research that reveal the independent effects of shift work and sleep on mental health, this study focuses on the interconnection between shift work, sleep, and depressive symptoms. Guided by the Stress Process Model (SPM), I examine the association between shift work and depressive symptoms and investigate whether sleep duration, sleep quality (insomnia symptoms), and sleep latency (the time it takes to fall asleep) mediate this relationship. Data was drawn from the age 50 health module of the National Longitudinal Survey of Youth 1979 cohort. The sample consisted of noninstitutionalized adults aged 51-60 (N=5,386). Findings show that shift workers had increased odds of short sleep, insomnia symptoms, and increased sleep latency compared to non-shift workers. Moreover, shift work was associated with increased depressive symptoms. However, part of the effect of shift work on depressive symptoms was indirect, operating through sleep. Specifically, short sleep during the week and on the weekend as well as insomnia symptoms mediated the relationship between shift work and depressive symptoms. The findings suggest that while engaging in shift work can negatively affect mental health, improving sleep duration and sleep quality can be effective in reducing the harmful effects of engaging in shift work during late midlife.


United States
Sleep disturbances in people living with cognitive impairment (CI) may impose a great burden on caregivers. We examined the relationship between objective and subjective sleep measures in people living with CI and caregiver depression and mastery via a secondary analysis of The Healthy Patterns Clinical Trial (NCT03682185) baseline data (n=170). Objective sleep variables included total sleep time and sleep efficiency derived from 3 nights of actigraphy. Subjective sleep measures included PROMIS Sleep Related Impairment, Pittsburgh Sleep Quality Index, and Epworth Sleepiness Scale. Caregiver measures included Center for Epidemiological Studies Depression Scale and Caregiver Mastery Scale. People living with CI were female (67%), Black (80%), with mean age 73.4 ± 8.7. Caregivers were female (81%), family caregivers (80%) with mean age 56.5 ± 14.7. We used multiple regression analysis, adjusting for cognition, and examined if there were differences by caregiver gender. Poorer subjective sleep quality was significantly associated with more caregiver depression (B=0.407, SE= 0.198, p = 0.042). There were no significant sleep predictors for caregiver mastery; however, there was a moderating effect of gender on the association between subjective sleep quality and caregiver mastery. Female caregivers had increased caregiver mastery compared to males when the person living with CI had better sleep quality (B=0.555, SE= 0.218, p = 0.012). This study found that people living with CI sleep characteristics differentially influence caregiver outcomes. Sleep should be assessed using a combination of objective and subjective sleep measures in people living with CI to inform providers when interventions are needed.

GOLDILOCKS AT WORK: JUST THE RIGHT AMOUNT OF JOB DEMANDS MAY BE NEEDED FOR YOUR SLEEP HEALTH
Monica Nelson 1 , Soomi Lee 1 , Tammy Allen 1 , Orfeu Buxton 2 , David Almeida 2 , and Ross Andel 1 , 1.

University of South Florida, Tampa, Florida, United States, 2. The Pennsylvania State University, University Park, Pennsylvania, United States
Objectives: It has been reported that job demands affect sleep, but how different levels of job demands affect sleep remains unclear. We examined whether curvilinear relationships exist between job demands and multiple sleep health outcomes. Design: Cross-sectional analyses with linear and quadratic effects, using self-administered survey data. Setting: A national sample of U.S. adults. Participants: Workers from Midlife in the United States Study (MIDUS2; n=2,927). Measurements: The Job Content Questionnaire assessed overall and five specific aspects of job demands (intensity, role conflict, work overload, time pressure, and interruptions). Habitual sleep health patterns across five dimensions (regularity, satisfaction/quality, daytime alertness, efficiency, and duration) were assessed. Age, sex, race/ethnicity, marital/partnered status, education, job tenure, work hours, body mass index, smoking status, and study sample were covariates.
Results: There were significant linear and quadratic relationships between job demands and sleep outcomes. Specifically, the linear effects indicated that higher job demands were associated with degraded sleep health, such as shorter duration, greater irregularity, greater inefficiency, and more dissatisfaction. The quadratic effects, however, indicated that the rate of degrade was decelerated in terms of sleep regularity and efficiency, such that these sleep outcomes were best with moderate levels of job demands. These effects were found for overall job demands as well as specific aspects of job demands. Stratified analyses further revealed that these curvilinear associations were mainly driven by participants with low job control.
Conclusions: Moderate levels of job demands, especially if combined with adequate job control, are related to better sleep health. Aging, 2022, Vol. 6, No. S1